1. Field of the Invention
The present invention relates to an electrostatic ink-jet recording head using electrified toner as ink material, and more particularly to an electrostatic inkjet recording head which performs recording by ejecting electrified toner from the nozzle of the head by the action of an electric field.
2. Description of the Prior Art
An electrostatic ink-jet recording head according to the prior art, disclosed in the Japanese Patent Laid-open No. 61-57343 Published on Mar. 24, 1986 for example, is provided with an ink chamber, having an ink inlet, for temporary storage of ink, an ink path leading to this ink chamber, and nozzles. An ink ejecting hole is provided at the tip of each nozzle. The bottom face of the ink chamber, the ink path and the bottom face of the nozzles are linearly arranged on the same plane to reduce resistance to the ink flow. At the tip of each nozzle is provided an ejection electrode for controlling the ejection of ink, and either the ink chamber or the ink path is equipped with an auxiliary electrode. An opposite electrode is arranged in a position at a prescribed distance from the tip of the nozzle. The ink includes toner electrified, positively for instance, in an insulating ink solvent. The opposite electrode has a potential which can electrically attract the electrified toner.
First, an electric field is formed by supplying a prescribed voltage to the auxiliary electrode. In response to the effect of this electric field, there is witnessed an electrophoretic phenomenon in which electrified toner in the ink solvent moves toward the ejecting hole of the nozzle, resulting in concentration of the electrified toner in the tip portion of the nozzle. As a voltage is applied in this state to the ejection electrode at the tip portion of the nozzle, a strong electric field works on the electrified toner in the tip portion of the nozzle, and the grains of the electrified toner, while being strongly attracted by the opposite electrode, fly from the ejecting hole. If recording paper is arranged on the opposite electrode side then, printing will take place. After the ejection of the electrified toner, in order to make up for any shortage of ink (electrified toner) in the nozzle, a member made of porous material is provided in either the ink chamber or the ink path, so that the porous member can serve to effectively supply ink, consisting of electrified toner, in the ink chamber to the nozzle.
However, production of this electrostatic ink-jet recording head according to the prior art requires the arrangement of a porous member in either the ink chamber or the ink path, resulting in a disadvantageously complex manufacturing process. Moreover, since the ejection electrode and the auxiliary electrode are arranged on the same plane and at a distance from each other to prevent their short-circuiting, the packaging area is correspondingly enlarged, inviting another disadvantage of a greater head size. Furthermore, if the number of nozzles is increased, the wiring area for the signal electrode and the auxiliary electrode will be enlarged, resulting in correspondingly greater dimensions of the ink-jet recording head.